Create another bootable USB Flash using one of the following methods: From Linux (.img and dd command) or from Windows (.iso and unetbootin.exe ) as shown below.

1- From Linux

If you already have a desktop or laptop Linux system:

The easiest way to make a USB Flash for Debian:you need a Linux system, web browser and Internet connection, get the .img file from:live.debian.net (main web page and find the iso archive. As of now it's the following link but it seems to change over time).